by Judith Curry
A new article in the Economist responds to the recent article in The New Republic, discussing the policy implications of the ‘pause.’
Mr Cohn does his best to affirm that the urgent necessity of acting to retard warming has not abated, as does Brad Plumer of the Washington Post, as does this newspaper. But there’s no way around the fact that this reprieve for the planet is bad news for proponents of policies, such as carbon taxes and emissions treaties, meant to slow warming by moderating the release of greenhouse gases. The reality is that the already meagre prospects of these policies, in America at least, will be devastated if temperatures do fall outside the lower bound of the projections that environmentalists have used to create a panicked sense of emergency. Whether or not dramatic climate-policy interventions remain advisable, they will become harder, if not impossible, to sell to the public, which will feel, not unreasonably, that the scientific and media establishment has cried wolf.
Given the so-far unfathomed complexity of global climate and the tenuousness of our grasp on the full set of relevant physical mechanisms, I have favoured waiting a decade or two in order to test and improve the empirical reliability of our climate models, while also allowing the economies of the less-developed parts of the world to grow unhindered, improving their position to adapt to whatever heavy weather may come their way. I have been told repeatedly that “we cannot afford to wait”. More distressingly, my brand of sceptical empiricism has been often met with a bludgeoning dogmatism about the authority of scientific consensus.
Of course, if the consensus climate models turn out to be falsified just a few years later, average temperature having remained at levels not even admitted to be have been physically possible, the authority of consensus will have been exposed as rather weak. The authority of expert consensus obviously strengthens as the quality of expertise improves, which is why it’s quite sensible, as matter of science-based policy-making, to wait for a callow science to improve before taking grand measures on the basis of it’s predictions.
As a rule, climate scientists were previously very confident that the planet would be warmer than it is by now, and no one knows for sure why it isn’t. This isn’t a crisis for climate science. This is just the way science goes. But it is a crisis for climate-policy advocates who based their arguments on the authority of scientific consensus.
But [Cohn's] attempt to minimise the political relevance of [the pause] is unconvincing. He writes:
But the “consensus” never extended to the intricacies of the climate system, just the core belief that additional greenhouse gas emissions would warm the planet.
If this is true, then the public has been systematically deceived. As it has been presented to the public, the scientific consensus extended precisely to that which is now seems to be in question: the sensitivity of global temperature to increases in atmospheric carbon dioxide. Indeed, if the consensus had been only that greenhouse gases have some warming effect, there would have been no obvious policy implications at all.
We have not been awash in arguments for adaptation precisely because the consensus pertained to now-troubled estimates of climate sensitivity. The moralising stridency of so many arguments for cap-and-trade, carbon taxes, and global emissions treaties was founded on the idea that there is a consensus about how much warming there would be if carbon emissions continue on trend. The rather heated debates we have had about the likely economic and social damage of carbon emissions have been based on that idea that there is something like a scientific consensus about the range of warming we can expect. If that consensus is now falling apart, as it seems it may be, that is, for good or ill, a very big deal.
JC comment: Houston’s article hits the nail on the head re the policy implications of the pause for policy and for the consensus. This statement struck me in particular:
Indeed, if the consensus had been only that greenhouse gases have some warming effect, there would have been no obvious policy implications at all.
This statement reflects the folly of the ‘speaking consensus to power’ approach of climate change policy making, and danger of a manufactured consensus on climate change to the healthy evolution of climate science. We’ve lost decades in climate science by failing to pay adequate attention to natural climate variability. By failing to pay adequate attention to uncertainty and natural climate variability, the climate community is facing the following prospect:
If that consensus is now falling apart, as it seems it may be, that is, for good or ill, a very big deal.